Quantification of plant charatcteritics associated with yiled increase is important in crop breeding programs. Regression models can be used for this purpose. Different genotypes of faba bean were evaluated using a randomized complete block design with three replications in 2014-2015 in Agriculture Research Station of Gorgan, Gorgan, Iran. Regression model revealed that faba been seed yield can be increased from 1665 kg.ha-1 to 2880 kg.ha-1 (1215 kg,ha-1 increase). It was found that this increase can be achieved by manipulation of four plant traits, i.e., plant height, pod number per plant, seed number per pod, and days to flowering. There was no significant negative correlation between the traits. Optimizing of these traits, within the observed range in the field experiment, can increase faba bean seed yield by 1215 kg.ha-1. The contribution of each trait in this increase was estimated: plant height by 503 kg.ha-1, pod number per plant by 344 kg.ha-1, seed number per pod by 327 kg.ha-1 and days to flowering by 41 kg.ha-1. It was concluded that using regression models would be helpful for increasing the efficiency of faba been breeding programs in Gorgan, Iran.